A UNC-affiliated startup is advancing gene therapy to help patients suffering from a rare disease that can lead to vision loss.
The company, known as RainBio, is developing a particular type of gene therapy to combat blindness in patients with Mucopolysaccharidosis type I.
MPS I is caused by mutations in a gene, which leads to the absence of the corresponding enzyme. Without this enzyme, different organs and tissues of the body enlarge, resulting in debilitating conditions, including corneal clouding, which creates vision impairment. But RainBio aims to treat this.
RainBio Co-Founder Matthew Hirsch, an associate professor at UNC, said he began work six years ago on what would become the startup’s first product after connecting with Dr. Joanne Kurtzberg at Duke University, who treated MPS I patients with stem cell transplantation. Despite improving mobility and neurological processes, Kurtzberg found her patients still went blind due to corneal clouding.
She proposed this type of gene therapy, adeno-associated virus gene therapy, to correct vision loss. RainBio’s product works by injecting the virus into the eye, which is harmless to patients. The virus acts as a delivery vehicle for a sequence that produces protein that the patients lack, Hirsch said.
“What we are using is just a protein capsid,” Hirsch said. “Inside is just the single stranded piece of DNA, and in that DNA the only thing that encodes protein is the sequence that we engineer inside of it. Then it makes the protein that the patients are deficient for.”
Fran Martin, president of RainBio, said these therapies promise patients only have to complete the therapy one time.
“You just get the gene in your system — the corrected gene in your system — one time and your body and your cells are able to have the corrected genetic code,” Martin said.
The product has a Pre-IND, or pre-investigational new drug, status with the Food and Drug Administration, which means the FDA has not yet permitted a Phase I clinical trial, Hirsch said.
Martin said, while no human patients have received the RainBio gene therapy product, the company has completed three cohorts of animal testing.
The startup conducted animal testing on dogs with corneal clouding due to MPS I and found the gene therapy to reverse the disease and prevent progression. Additionally, the group conducted studies on rabbits without MPS I, which demonstrated tolerability and safety, Hirsch said.
The company hopes to get their product on the market in 2026, but there are many steps to complete before this is possible. RainBio must complete several rounds of meetings with the FDA before it can begin clinical trials or manufacturing the treatment.
Charlotte Pete, president and founder of Students for Rare, a club at UNC that seeks to raise awareness for uncommon diseases, said she hopes RainBio inspires others to put in the hard work to develop more rare disease therapies.
“Living with a rare disease not only can impact you physically, but also has substantial impacts on one's mental health, so I believe RainBio will drastically change people's lives and give them not only their sight but a newfound sense of independence and confidence," Pete said.
RainBio received financial support from the department of ophthalmology at UNC in the early stages of its research. Innovate Carolina provided guidance in forming the company and transferring licensing materials, Hirsch said.
Innovate Carolina's Kelly Parsons, associate director of technology commercialization in the UNC Office of Technology Commercialization, said in a statement to The Daily Tar Heel that Innovate Carolina helps companies that have UNC-licensed technology to attract investments and resources, and protect their intellectual property.
Hirsch hopes the company’s work will open the door for future corneal gene therapy innovations.
“Hopefully, with our colleagues and the community, you know, we can start attacking other diseases to help a bigger population,” Hirsch said. “So, this is kind of like a gateway drug and, if we can get it into just a few patients, if it helps then collectively, with our colleagues we will have a bigger impact in just improving vision in general.”
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